Then, cut the mold along one side. The super soft and stretchy Dragon Skin® silicone can then be pulled away from the antlers. Seat the rubber mold in the mother mold to prepare it for casting. Use drywall screws to tightly close the shell and secure it to the board. Mix and pour Smooth-Cast® 300 liquid plastic into the mold. The casting is an exact replica of the original antlers.